U.S. patent number RE31,084 [Application Number 06/035,572] was granted by the patent office on 1982-11-23 for swaging dies.
Invention is credited to Cedric G. Birks.
United States Patent |
RE31,084 |
Birks |
November 23, 1982 |
Swaging dies
Abstract
Coacting swaging dies for swaging a splice sleeve onto a
reinforcing bar. The dies each include a recess in their coacting
surfaces. The recess in each surface includes at least two
longitudinally extending ribs projecting from said recess for
forming longitudinal indentations in the splice tube when said tube
is squeezed between said dies. The lands between immediately
adjacent ribs are concave. The ribs are so located that when the
dies are in contact the recesses conjoin to form an overall
polygonal shaped opening, with the ribs being equidistantly spaced
thereabout.
Inventors: |
Birks; Cedric G. (Leeds, West
Yorkshire, GB2) |
Family
ID: |
10341178 |
Appl.
No.: |
06/035,572 |
Filed: |
May 3, 1979 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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Reissue of: |
710815 |
Aug 2, 1976 |
04067224 |
Jan 10, 1978 |
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Foreign Application Priority Data
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Aug 4, 1975 [GB] |
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32601/75 |
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Current U.S.
Class: |
72/416; 29/517;
72/409.19 |
Current CPC
Class: |
B21F
15/06 (20130101); E04C 5/165 (20130101); Y10T
29/49929 (20150115) |
Current International
Class: |
B21F
15/06 (20060101); B21F 15/00 (20060101); D07B
9/00 (20060101); E04C 5/16 (20060101); B21J
013/02 (); B21D 037/10 () |
Field of
Search: |
;72/416,412,415,470,367,402,453.01,453.15,410,417 ;29/517 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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2240336 |
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Jul 1974 |
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FR |
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1432888 |
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Apr 1976 |
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GB |
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Primary Examiner: Godici; Nicholas P.
Assistant Examiner: Crosby; Gene P.
Attorney, Agent or Firm: Caesar, Rivise, Bernstein &
Cohen, Ltd.
Claims
What is claimed as the invention is:
1. For use in a press for swaging a sleeve onto a bar a pair of
coacting high strength metal .Iadd.compression .Iaddend.dies, each
of said dies comprising a recess extending parallel to the
longitudinal axis of said bar .[.and having a ribbed medial portion
including.]..Iadd., said recess including a medial portion of
uniform size and shape extending along its entire length, the
surface of the medial portion of the recess being in the form of
.Iaddend.a plurality of radially projecting ribs extending along
said axis, said ribs projecting .[.upward.]. .Iadd.radially inward
.Iaddend.from said .[.recess.]., .Iadd.surface .Iaddend.with the
recess portions .Iadd.of said recess .Iaddend.between immediately
adjacent ribs being concavely relieved, the ribs being so located
that when said dies are in contact with each other their
.[.recesses.]. .Iadd.medial recess portions .Iaddend.conjoin to
form a polygonal opening .Iadd.of uniform profile along its
length.Iaddend., with the concave relieved portions of the dies
equidistantly spaced about the periphery of said polygonal
opening.Iadd., said dies being arranged to be brought together in a
radial direction by said press, with said sleeve and said bar
disposed therebetween to compress the sleeve onto the bar
.Iaddend.so that .[.upon swaging.]. the material of the sleeve
adjacent each of said concave relieved portions conveniently flows
into said relieved portions.
2. The dies of claim 1 wherein each die includes at least three
longitudinally extending ribs.
3. The dies of claim 1 wherein each of said dies comprises at least
four longitudinally extending ribs.
4. The dies of claim 1 wherein each of said dies include plural
ribs whereupon said cylindrical opening is octagonal.
5. The dies of claim 4 wherein each recess has a
semi-frusto-conical portion at either side of the ribbed portion
and opening outward thereof.
6. The dies of claim 5 wherein each semi-frusto-conical portion
opens into a semi-cylindrical portion, the outmost edge of which is
chamfered.
Description
This invention relates generally to die parts and more particularly
to die parts for use in swaging a splice sleeve onto bars or wire
ropes in end-to-end or overlapping relation.
Various apparatus have been disclosed in the prior art and are
commercially available incorporating a pair of dies for swaging
elongated metal members such as cables or reinforcing bars in an
end-to-end relation. See for example, U.S. Pat. No. 676,292
(Wigtel) and U.S. Pat. No. 2,533,943 (Klein) and British Pat. No.
1,293,954 (Zublin). Various dies of the prior art, due to their
particular construction present several drawbacks. For example, due
to the construction of some prior art dies the use of such dies
requires at least two mutually perpendicular swaging operations or
bites to effect the securement of a sleeve onto a bar. This is a
time consuming and expensive operation. In addition, in some
applications, e.g., wherein the members to be joined are disposed
in a confined area or disposed in a closely spaced array swaging in
mutually perpendicular directions may be rendered extremely
difficult if not precluded by the physical space available.
Accordingly, it is a general object of this invention to provide
dies for swaging sleeves on the reinforcing bars which overcomes
the disadvantages of the prior art.
It is a further object of this invention to provide a pair of
swaging dies which enable the maximization of swaging bite lengths
while retaining the ability to operate in very confined spaces.
It is still a further object of this invention to provide a pair of
swaging dies which produce an efficient distribution of swaging
sleeve material during the swaging operation.
These and other objects of the instant invention are achieved by
providing for use in a press for swaging a sleeve onto a bar a pair
of coacting high strength metal dies. Each of said dies comprising
a longitudinally extending recess having a ribbed medial portion
including at least two longitudinally extending ribs projecting
upward from the recess. The ribs are so located that when the dies
are in contact with each other a polygonal recess is produced with
the ribs of the dies equidistantly spaced about the periphery of
said polygonal recess.
Other objects and many of the attendant advantages of the instant
invention will be readily appreciated as the same becomes better
understood by reference to the following detailed description when
considered in connection with the accompanying drawing wherein:
FIG. 1 is a side elevational view of a pair of coacting swaging
dies in accordance with the instant invention;
FIG. 2 is a sectional view taken along line 2--2 of FIG. 1;
FIG. 3 is an exploded perspective view of a sleeve to be swaged
onto a pair of reinforcing bars by the dies of the instant
invention; and
FIG. 4 is a perspective view of the dies forming a swage joint.
Referring now to the various figures of the drawing wherein like
reference characters refer to like parts, there is shown in FIG. 1
a pair of coacting opposed metal swaging die parts 20. The pair of
die parts includes an upper die part 22 and a lower die part 24.
Each die part is adapted to be secured in a press, not shown. In
U.S. patent application Ser. No. 710,489 filed herewith .Iadd.now
Patent No. 4,047,420 .Iaddend.and whose disclosure is incorporated
by reference herein, there is disclosed a press particularly suited
for using the dies of the instant invention to swage a sleeve onto
reinforcing bars to splice them together. The press disclosed and
claimed in said application forms no part of the invention of the
instant application.
As can be seen in FIGS. 1 and 3, each die part 22 and 24 has a
recess 26 therein. Each recess is formed of a substantially
central, generally semi-cylindrical portion 28 which communicates
at each end with a semi-frusto-conical portion 30. A semi-circular
cylindrical portion 32 is contiguous with and communicates with the
semi-frusto-conical portion 30. The extreme ends of the cylindrical
portion 32 are chamfered as at 34.
A die half 36 (FIG. 1) is constituted by the inner surface of each
semi-cylindrical portion.
In accordance with a preferred embodiment of this invention each
die half has plural ribs 38 (FIG. 1) extending longitudinally long
the mid-portion of the recess 26. Each rib includes a generally
planar top portion 40. the ribs 38 project inwardly of the recess
and are so located that when the die pair 20 is in the position
shown in FIG. 1 the ribs 38 in the recesses 26 are spaced
equidistantly apart around the conjoined central and generally
polygonal shaped opening or recess which is formed thereby. The
portion 42 of the recesses 26 between immediately adjacent ribs 38
are of generally concave shape as shown clearly in FIG. 1.
As can be seen in the embodiment shown in FIG. 1 each die of the
die pair includes four ribs equidistantly spaced apart so that when
the dies are together the conjoined central opening formed by their
recesses is of octagonal shape.
It should be pointed out at this juncture that the number of ribs
in each die recess can vary, e.g., there may be two, three, four or
more ribs in each die recess, but it is essential to the invention
that the die opening or recess have an overall polygonal shape. It
is also preferred that each die of the die pair includes the same
number of ribs, although it is contemplated that the dies of the
die pair 20 may be so constructed as to form an odd number of ribs
when the dies of the pair abut.
In use the die parts 22 and 24 are located in a press, preferably
one constructed in accordance with the teachings of the
aforementioned co-pending United States patent application. That
press comprises a cylinder having a longitudinal axis with a piston
therein and reciprocal along the axis. The cylinder has an end and
a pair of spaced arms extending from the end in a direction
generally parallel to the cylinder with the distance between the
outer surface of the arms measured in a direction transverse to the
longitudinal axis being less than the outer diameter of the
cylinder. A bridging member or cap is detachably secured to and
bridges the arms. The bottom die part 24 is secured to the free end
of the piston and the upper die part 22 is secured to the cap.
Movement of the piston along the longitudinal axis towards the cap
effects the concomitant movement of the lower die part toward the
upper die part to urge the die parts together.
As shown in FIGS. 1 and 2, a plurality of screw holes 44 are
provided in each of the die parts 22 and 24 for effecting the
connection of the die part to the corresponding portions of the
press (not shown).
As shown in FIGS. 3 and 4, die parts 22 and 24 may be used to
secure together two reinforcing bars 46 by means of a metal splice
tube 48. To that end, one end of one reinforcing bar 46 is placed
in one end of the splice tube 48 and the two parts 46 and 48 are
thereafter swaged together by a force applied, via die parts 22 and
24, in a press. The second bar 46 is then located in the other end
portion of the sleeve 48. The connection between the bars 46 is
completed by swaging along the length of the splice tube 48 in
successive swaging operations or bites. In each case the metal of
the splice is deformed into tight engagement with the bar, with
little or no elongation of the splice. As a consequence, the number
of bites necessary to secure a splice to the bar can be reduced to
a minimum.
As will be appreciated by those skilled in the art, the ribs on the
dies are effective for causing equidistantly spaced indentations
about the periphery in the swaged sleeve, thereby ensuring an
efficient distribution of metal during the swaging operation.
The concave portions of lands 42 between adjacent ribs 38 effect
the formation of a plurality of peripherally spaced longitudinally
extending ribs 50 (FIG. 4) in the formed connection between bars
46.
By using the dies of the instant invention a splice sleeve can be
pressed onto the reinforcing bars 46 in a single pressing
direction, thereby avoiding the necessity of two mutually
perpendicular swaging operations, or bites, as has characterized
the use of some swaging dies. The number of bites will, of course,
depend upon the sleeve length. It should be pointed out at this
juncture that it is a feature of the dies of the instant invention
that when they are utilized in a press constructed in accordance
with the teaching of the aforenoted co-pending application, the
longest possible bite length may be achieved during the splicing
operation while retaining the ability to operate in very confined
spaces.
In one practical example of a swage connection formed as described
hereinabove the mean tensile strength achieved was 556N/mm.sup.2
with little significant difference between maximum and minimum
values.
Without further elaboration the foregoing will so fully illustrate
my invention that others may, by applying current or future
knowledge, readily adapt the same for use under various conditions
of service.
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